1. Field of the Invention
This invention relates to the field of wave-action energy-harnessing apparatus and more particularly to a phase control mechanism for a wave energy apparatus utilizing a float reciprocable upwardly and downwardly responsive to the maximum differences between wave crests and troughs.
2. Background Information
The present invention is an improvement on sea wave energy conversion apparatus of the kind described in U.S. Pat. Nos. 3,930,168 and 4,599,858. In devices of this type, wave energy is converted into another form such as electrical energy or is directly harnessed to perform a particular task such as pumping a liquid. Typically, a buoyant body is operative between an upper position and a lower position in a platform which is relatively stationary with respect to the motion of the waves containing the energy to be harnessed. As the floating body is lifted from a lower position to an upper position by the passing of the wave, energy is absorbed from the wave. Then, as the wave passes, the body is allowed to fall into the trough and the potential energy which has been absorbed by the floating body is transformed into kinetic energy. Further, as discussed in Count, Power from Sea Waves, Academic Press, New York, 1980, maximum power absorption in regular waves occurs at resonance. In Count, it was reported that any method of establishing a relationship wherein force and velocity are in phase is equally as good as resonance in obtaining maximum power absorption. In Count, a magnetic locking mechanism for the floating body was established. An analog circuit which could automatically determine the position of the floating body at zero velocity was made and a signal from a wave close to the position of the floating body was fed into a computer. The computer gave out a trigger signal that released the floating body at a time such that the maximum velocity of the floating body occurred at the moment of local peaks and troughs.
One form of wave energy conversion device is disclosed in U.S. Pat. No. 4,599,858 to La Stella and Tornabene. In that invention, a reciprocating shaft is gear coupled to a horizontal shaft and a braking mechanism is applied to a disk affixed to a horizontal shaft in order to retain the mechanism at an optimum point to be released at the passing of the next appropriate wave.